Thyroidal uptake and urinary excretion of I131 in different thyroid disorders by whole body counter

Abstract

The present study includes 46 cases of thyroid disorders and 70 apparently normal individuals. All the cases had no other endocrine disorders. After oral administration of 2-5 uci of I131, the distribution pattern of I131 was recorded by whole body counter. Serum PBI was determined in all the cases to assess the iodine balance of the body. Whole body retention and urinary excretion of I131 was found directly associated with each other in normal as well as in various thyroid states. Therefore, urinary excretion may serve as a useful criterion for the determination of thyroid activity. Similarly, tracer dose was decreased to extremely low levels, permitting the use of isotopes with longer decay periods in the same minimum dose.